It is entirely possible he didn't take any significant knock, but instead that smaller impacts are now affecting him. If so, it is time to call it a day. As ever, this will become a prolonged, dragged out affair, but it is the only sensible, humane way forward. I would be concerned if Wasps attempt to play him again. Support him, yes, as he will need it. But, I think, the future for him is clear.